singletons

简明释义

英[ˈsɪŋɡltənz]美[ˈsɪŋɡəltənz]

n. 使用单件；单件物品（singleton 的复数）

英英释义

单词用法

同义词

反义词

例句

1.The web is a multiunser environment, so holding application state in static objects such as singletons is likely to cause issues

Web是一个多用户环境，所以在一个静态对象中（如singleton）保持应用状态是有可能引起问题的。

2.Being married means you are at half the risk of getting dementia compared with singletons, Swedish researchers reported this month.

结婚意味着你得老年痴呆症的风险比单身的人要低一半，瑞典研究人员在本月的报告中称。

3.By default, services can be singletons or are created on a per-request basis.

在默认情况下，服务可以是单实例的，也可以为每个请求创建服务实例。

4.Being married means you are at half the risk of getting dementia compared with singletons, Swedish researchers reported this month.

结婚意味着你得老年痴呆症的风险比单身的人要低一半，瑞典研究人员在本月的报告中称。

5.Two singletons will be created if the constructor runs and simultaneously another thread calls the method.

当该构造方法运行的同时，恰好被另一线程访问，两个单例对象将被创建。

6.Multiple singletons in two or more virtual machines.

多个单例对象存在于两个或多个虚拟机中。

7.In the context of design patterns, singletons are used to ensure a class has only one instance and provides a global point of access.

在设计模式的上下文中，单例用于确保一个类只有一个实例，并提供一个全局访问点。

8.In programming, a class that allows only one instance is often referred to as a pattern for creating singletons.

在编程中，允许仅创建一个实例的类通常被称为创建单例的模式。

9.The concept of singletons can help prevent multiple instances of a service from being created in an application.

单例的概念可以帮助防止在应用程序中创建多个服务实例。

10.Many developers use singletons to manage shared resources like database connections.

许多开发者使用单例来管理共享资源，比如数据库连接。

11.The game engine uses singletons to manage the state of the game across different scenes.

游戏引擎使用单例来管理不同场景之间的游戏状态。

作文

In the realm of programming and software design, the term singletons refers to a design pattern that restricts the instantiation of a class to one single instance. This concept is particularly useful in scenarios where a single point of control is necessary, such as in managing shared resources or configurations. By ensuring that only one instance of a class exists, developers can avoid issues related to multiple instances that could lead to inconsistent states or resource conflicts. The singleton pattern not only simplifies resource management but also enhances performance by reducing the overhead associated with creating and maintaining multiple instances.Moreover, the implementation of singletons often involves a static method that returns the instance of the class. This ensures that the instance is created only when it is needed for the first time, following the lazy initialization principle. For instance, consider a logging service that should log messages throughout an application. If multiple instances of the logging service were allowed, it could result in scattered logs and confusion. By using the singleton pattern, we can ensure that all logging is centralized, making it easier to manage and analyze.However, the use of singletons is not without its drawbacks. Critics argue that they can introduce global state into an application, which makes testing and debugging more challenging. When a class is designed as a singleton, it becomes tightly coupled to its implementation, making it harder to substitute with mock objects during unit testing. This can lead to less maintainable code over time, especially in larger applications where flexibility is crucial.The debate surrounding the use of singletons often centers on the balance between their benefits and potential pitfalls. While they can provide a straightforward solution for managing shared resources, developers must be cautious about overusing this pattern. It is essential to evaluate whether a singleton is truly necessary or if a different design pattern might better suit the requirements of the application.In conclusion, singletons play a significant role in software development by providing a controlled access point to shared resources. They are particularly advantageous in scenarios requiring centralized management. However, developers should weigh the advantages against the potential challenges they may introduce, particularly concerning testability and maintainability. Ultimately, understanding when and how to implement singletons effectively can lead to more robust and efficient software solutions.

在编程和软件设计领域，术语singletons指的是一种设计模式，它限制了一个类的实例化为单个实例。这个概念在需要单一控制点的场景中尤为有用，例如管理共享资源或配置。通过确保只有一个类的实例存在，开发者可以避免与多个实例相关的问题，这些问题可能导致不一致的状态或资源冲突。singleton模式不仅简化了资源管理，还通过减少创建和维护多个实例所需的开销来提高性能。此外，singletons的实现通常涉及一个静态方法，该方法返回类的实例。这确保了实例仅在第一次需要时被创建，遵循懒初始化原则。例如，考虑一个应在整个应用程序中记录消息的日志服务。如果允许多个日志服务的实例，将导致日志分散和混乱。通过使用singleton模式，我们可以确保所有日志都集中管理，从而更容易进行管理和分析。然而，使用singletons并非没有缺点。批评者认为，它们可能会在应用程序中引入全局状态，这使得测试和调试变得更加困难。当一个类被设计为singleton时，它与其实现紧密耦合，这使得在单元测试期间用模拟对象替代变得更加困难。这可能导致代码在更长时间内变得不易维护，特别是在较大的应用程序中，灵活性至关重要。围绕使用singletons的争论通常集中在它们的好处与潜在陷阱之间的平衡上。尽管它们可以为管理共享资源提供简单的解决方案，但开发者必须谨慎对待这种模式的过度使用。评估singleton是否真的必要，或者是否有其他设计模式可能更适合应用程序的需求是至关重要的。总之，singletons在软件开发中扮演着重要角色，通过提供对共享资源的受控访问点。它们在需要集中管理的场景中特别有利。然而，开发者应该权衡这些优势与它们可能引入的潜在挑战，特别是在可测试性和可维护性方面。最终，理解何时以及如何有效地实施singletons可以导致更强大和高效的软件解决方案。